Later on I'll try to go over the chalk issues and either close them, or link to cards, or maybe create new ones

But if folks are interested in pushing on this, it might be worth skimming over

One interesting question that I am pondering: my hope is that we'll develop a nice, ergonomic type library that is eventually just "the library" that we use for rust types, with the role of the TypeInterner trait being really just to define what kind of memory management strategy we want (and maybe to help us in code management, by letting us differentiate between "input" and "output" types and things).